Process of hardening copper boiler-tubes.



P. D. JOHNSON.

PROCESS! OF HARDENING COPPER BOILER TUBES. APPLIOATI N PI'LBD JULY17, 1912.

6023257296365; Z g ggr ,w! m P7217170 2. (lo/2725022 1 617M 3 l .flarn/qys co MEIA PLANOGRAPH co WASH NaToN D c Patented Nov. 11, 1913.

i To all whom it may concern s Paras-r OFFICE.

PHILIP :o. :ionnson, or CHICAGO, rnnrivors.

rnoenss or rrannnurue oorrnn sornun rueus.

sp ci e ff racers Patented Nov. 11*, 1913.

Application filed as 17, 1am. semi No. viaoee;

Be it known that LPnILir I). JoHNsoN,

a citizen of the United States, residingat Chicago, in the county of Cookandfitate of Illinois, have invented a certain new and useful Improvement in Processes of Han dening Copper Boiler-Tubes, of which the following is a full, clear, concise, and exact description, reference being had to the accompanying drawings; forming a part oi this specification.

My invention relates to an improvedproc ess or method of hardening boiler tubes of copper or brass and is particularly adapted to renewing these tubes in boilers after they have been overheated and softened by improper use of the boiler.

its is wellhnown in the art, copper tubes are frequently employed in automobile boilers and, while they give good results in. many ways on account of their high conductiVity,QtheV are subject to the disadvantags that they are readily overheated if the water should become. too low in the boiler for any reason and when thus overheated or burned they lose their temper or hardness and when again subjected to pressure they readily collapse and cause leaks in the boiler between thesends of the fines and the boiler heads and prevent further use of the boiler untilthe same is repaired. I-leretm fore it has been necessary under such conditions to remove the softened and collapsed tubes and replace them with new ones, but

by my process the need for doing this is entirely eliminated, since the softened and collapsed tubes may be restored to proper shape and hardness simply and effectively so that the boiler maybe again used and successfully subjected to the same treatment as when the boiler was first made.

By my process in restoring or reclaiming a boiler damaged by overheating or burning, I first introduce water into the boiler under high pressure suflicient to collapse all of the tubes that have been softened by the burning. Any leaks that develop at the ends of the tubes are then stopped by expanding the tubes until all of the joints in the boiler rapidly rotated and at the same time moved longitudinally through one tube after anin them so as to make tight joints.

other. The spinning tool is of substantially the diameter of the hereof the boiler tubes and isvpointed so thatjas it moves through one collapsed tube after another, it opens up theflattened portlon and by itszmechanu cal manipulation of the metal the tube spins andflrardens it so that by the single operation of moving the rotating Itcol throiiigh the tube, the tube is restored both Under certain circumstances, it is. not necessaryto collapse thetubes as, torexample, when the boiler is so badly overheatedthat itis knownthat all of the tubesare injured, for in this case the spinning tool may be taken of slightly larger externaldiameter frequently but few oi them are injured and it would be a useless amount of work to treat all of them "as-described when only a small number of them were in need ofrt.

1n carrying out my lnvention, 1t Will be understood that it isnot necessary toemploy a particular form of mechanism carrying the spinning tool, Any mechanism that willimpart the necessary rotary and longitudinal motions to the tool may be employed. Thus, in many cases, it will be found convenient to employ an ordinary drill press to operate the spinning tool or, ii preferred, alathe may be so employed. On the other hand, if desired, special mech anism may be devised peculiarly adapted to rotate the arbor and teed it through the tubes, one after another, with a minimum amount of attention. on the part of the operator. As the particular mechanism which is employed for accomplishing this result does not constitute a part of the present invention, I have illustrated in the accompanying drawing a simple diagrammatic form of apparatus in order that the process may be clearly understood.

In the drawing illustrating my invention, I have shown a boiler consisting of the heads 1 and 2 connected together by the shell 3 surrounding the boiler tubes lwhich extend between the heads and are expanded The tubes l are shownas collapsed, either as a It is generally desirable, however, to collapse the damaged tubes, since to its proper shape and. proper hardness. r

result of the softening of the tubes by overheating or by the application of high water pressure, as described, and the boiler is assumed to be in condition for the hardening operation, all of the tubes 4 having been collapsed which are sufficiently softened to weaken them.

In the drawings an arbor 5 is shown as mounted in bearings 6 and 7 so that it may move longitudinally therein, the upper end of the arbor being connected by a rotatable lock 8 with a link 9, the other end of which engages a lever 10 pivotally supported at 11, so that by moving the lever 10 up and down the arbor. 5 is moved vertically in its bearings. The lower end of the arbor 5 has rigidly secured to it a spinning tool 12 of an external diameter substantially the same as the inner bore of the tubes 4:, and the lower end of the spinning too-l is pointed so that as it is moved down into the tubes 4 they will be spread from flattened condition gradually into circular form.

The arbor 5 has slidably mounted thereon a driving gear 13 which rotates the arbor by engagement with a keyway 14:. The gear 13 is engaged by a driving chain 15 which is driven by a gear 16 mounted upon a driving shaft 17 which may be actuated in any desired manner. In the drawings, the shaft 17 is shown as mounted in bearings 18 and provided with a crank 19 by which said shaft may be rotated. Obviously, power may be employed to rotate the shaft 17 and maybe communicated thereto in any desired manner.

Broadly considered, therefore, my inventlon conslsts 1n the method of reforming and rehardening distorted boiler tubes, although it is also applicable, as pointed out, to the rehardening of boiler tubes which have been softened or which are found to be toosoft for practical use after they are in place in a boiler, whether they have been distorted or not since the essential feature of the reforming operation is the mechanical manipulation of the surface of the tubes in place in the boiler heads by means of a suitable spinning tool. In practice it is frequently desirable to expand all of the tubes at each end to see that the joints are tight before subjecting them to water pressure. The tubes are then collapsed and treated as explained above.

What I claim is:

l. The process of restoring burned boiler tubes which consists in expanding the ends of the burned tubes to make tight joints in the heads of the boiler, collapsing the burned tubes by the application of pressure in the boiler, and restoring thetubes to circular cross-section and hardening them by means of a rotating spinning tool passing through them.

2. The process of repairing a tubular boiler in site which consists in first subjecting the tubes to pressure to cause them to collapse, and then restoring the tubes to cir cular cross-section and manipulating them by passing a rotating tool through them.

In witness whereof, I hereunto subscribe my name this 13th day of July, A. D., 1912.

PHILIP D. JOHNSON. WVitnesses:

ALBERT C. BELL, CLIFFORD C. DEWEEs.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents, Washington, D. G. 

